Security checkpoints refer to a road traffic scene monitoring system for taking pictures of, recording and processing all motor vehicles passing through a checkpoint location, relying on specific places on the road, such as checkpoint locations like toll stations, traffic or security inspection stations etc. Currently, high-definition checkpoint systems play an important role in applications such as security, criminal investigation, fighting against and preventing crimes, and coping with emergencies etc., especially in the application of criminal investigation, it requires seeking clues for criminal detection based on the stored checkpoint images, and this method has become an important technical means of criminal investigation and detection.
Criminal investigation and detection may need to look up history images of three months ago or a longer time ago, which requires security checkpoint images to be preserved for a long time, and preserving a large number of checkpoint images requires a very large storage space as more and more high-definition checkpoints have been constructed nowadays. The problem the high-definition security checkpoint system is currently faced with is: the problem of storing a large number of checkpoint images for a long time.
The Chinese patent application CN201210568309 is the closest technical solution of the present invention, which discloses a method for reducing storage spaces. This invention provides a method for reducing storage spaces of images, which addresses the problem of requiring a large storage space to store image signals in the monitoring system of the prior art.
Its technical solution is: obtaining an image signal by a camera, buffering the image signal and outputting a data signal, compressing the data signal and extracting the image data in GIF (Graphics Interchange Format) or JPG (Joint Photographic Experts Group) format, comparing the latest image data with the last updated image data in a register, if the comparison result exceeds a range, extracting the image data in JPG format, otherwise extracting the image data in GIF format.
The essence of its technical solution is: storing a low-resolution image in a memory when there is no difference from the obtained image, so that storage spaces are reduced. Though this method for reducing storage spaces by way of decreasing image resolutions reduces storage spaces, it also reduces a recognizable degree of critical information, and this loss of the critical information would seriously affect applying security checkpoint images in the criminal investigation.